1. Field of the Invention
The present invention relates to audio signal processing. More preferably, it is suitable for processing an audio signal received via a digital medium, a broadcast signal or the like.
2. Discussion of the Related Art
In a process for generating a downmix signal by downmixing an audio signal including at least one object into a mono or stereo signal, parameters are extracted from the object. Theses parameters are used in decoding the downmixed signal. And, positions and gains of the objects can be controlled by a selection made by a user as well as the parameters.
Objects included in a downmix signal should be controlled by a user's selection. However, when a user controls an object, it is inconvenient for the user to directly control all object signals. And, it may be more difficult to reproduce an optimal state of an audio signal including a plurality of objects than a case that an expert controls objects.